Gymnast, before upper horizontal bar, smears some magnesium powder on hand: formal name used at school is ” magnesium carbonate “, and people are called again usually ” magnesium powder “. Magnesium carbonate is very light in weight and has a strong hygroscopic effect. Athletes often sweat in their palms during competitions, which is very unfavorable for gymnasts and weightlifters. Because the wet and slippery palm will reduce the frictional force, making the athlete unable to hold the equipment, which not only affects the quality of the movement, but also causes the athlete to fall off the equipment in severe cases, causing mistakes and even injuries. Magnesium carbonate can suck center of the palm sweat, also can increase the frictional force between the center of the palm and apparatus simultaneously. In this way, the athlete can hold the apparatus with a firm grip, which is conducive to improving the quality of the action.